Simple Sitemaps for Multisite 1.0.4 error

i was recently prompted by the WPMU Update to install Sime Sitempas for Multisite v1.0.4

after installing, I get the following error:
"Fatal error: Cannot redeclare Incsub_SimpleSitemaps() (previously declared in /var/www/clients/client0/web1/web/wp-content/mu-plugins/simple-sitemaps.php:166) in /var/www/clients/client0/web1/web/wp-content/plugins/simple-sitemaps/simple-sitemaps.php on line 169?

i also have the all-in-one-SEO installed, would this cause a conflict? And if so, why am I being prompted to install the Simple Sitemap?

thanks, Ted